1. Technical Field
The present invention relates to a webbing retractor that houses a webbing, that is for restraining a vehicle occupant, in a state in which the webbing is taken-up on a take-up shaft.
2. Related Art
There are known webbing retractors that are structured so as to transmit the rotational force of a motor to a take-up shaft via a clutch, and take-up a webbing (see, for example Japanese Patent Application Laid-Open (JP-A) No. 2005-289259). At the clutch of the webbing retractor shown in JP-A No. 2005-289259, spring claws of a ring are inserted and disposed between a rotor and a gear wheel that is disposed at the outer periphery of the rotor. Relative rotation of the ring with respect to the gear wheel is restricted. The distal end portions of the spring claws engage with external teeth formed at the outer peripheral portion of the rotor. Due thereto, relative rotation between the rotor and the gear wheel is restricted.
In the webbing retractor of the above-described structure, when relative rotational force of greater than or equal to a predetermined value is applied between the rotor and the gear wheel, the spring claws elastically deform and the distal end portions of the spring claws are pulled-out from valley portions of the external teeth of the rotor, and the rotor and the gear wheel thereby rotate relatively (an overload releasing mechanism is operated).
Here, in the above-described webbing retractor, in order to further increase the load at which the overload releasing mechanism operates, the deformation resisting load of the spring claws must be increased. However, when the plate thickness or the width of the spring claws is increased in order to further increase the deformation resisting load of the spring claws, the shapes of the other parts must be changed.